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Piccoli" , corbet@lwn.net, mcgrof@kernel.org, keescook@chromium.org, yzaikin@google.com, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, linux@rasmusvillemoes.dk, ebiggers@google.com, peterz@infradead.org, ying.huang@intel.com, mchehab+huawei@kernel.org, Jason@zx2c4.com, daniel@iogearbox.net, robh@kernel.org, wangqing@vivo.com, prestwoj@gmail.com, dsahern@kernel.org, stephen.s.brennan@oracle.com References: <20220401202300.12660-1-alejandro.j.jimenez@oracle.com> From: Alejandro Jimenez Organization: Oracle Corporation In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SN4PR0501CA0125.namprd05.prod.outlook.com (2603:10b6:803:42::42) To SA1PR10MB5866.namprd10.prod.outlook.com (2603:10b6:806:22b::19) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 56fe2840-1ecf-48c3-846b-08da167bcbbd X-MS-TrafficTypeDiagnostic: CY4PR10MB1317:EE_ X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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Piccoli wrote: > On 01/04/2022 17:22, Alejandro Jimenez wrote: >> I noticed that in contrast to other kernel core parameters (e.g. kernel.panic, >> kernel.panic_on_warn, kernel.panic_print) crash_kexec_post_notifiers is not >> available as a sysctl tunable. I am aware that because it is a kernel core >> parameter, there is already an entry under: >> >> /sys/module/kernel/parameters/crash_kexec_post_notifiers >> >> and that allows us to read/modify it at runtime. However, I thought it should >> also be available via sysctl, since users that want to read/set this value at >> runtime might look there first. >> >> I believe there is an ongoing effort to clean up kernel/sysctl.c, but it wasn't >> clear to me if this entry (and perhaps the other panic related entries too) >> should be placed on kernel/panic.c. I wanted to verify first that this change >> would be welcomed before doing additional refactoring work. >> >> I'd appreciate any comments or suggestions. >> >> Thank you, >> Alejandro > Hi Alejandro, thanks for you patch. I have a "selfish" concern though, > I'll expose it here. > > I'm working a panic refactor, in order to split the panic notifiers in > more lists - good summary of this discussion at [0]. > I'm in the half of the patches, hopefully next 2 weeks I have something > ready to submit (I'll be out next week). > > As part of this effort, I plan to have a more fine-grained control of > this parameter, and it's going to be a sysctl, but not > "crash_kexec_post_notifiers" - this one should be kept I guess due to > retro-compatibility, but it'd be a layer on top oh the new one. It would be great to provide finer control and isolate the riskier modifiers. I am using crash_kexec_post_notifiers to control behavior of pvpanic and pstore and there is not an urgent need for my change, so I don't mind waiting for the new interface to evolve. Please copy me if possible on future submissions. Thank you, Alejandro > With that said, unless you have urgent needs for this patch to be > reviewed/merged , I'd like to ask you to wait the series and I can loop > you there, so you may review/comment and see if it fits your use case. > > Thanks, > > > Guilherme > > > [0] https://lore.kernel.org/lkml/YfPxvzSzDLjO5ldp@alley/